Conventionally, experiments of FRET (Fluorescence resonance energy transfer) and FRAP (Fluorescence Recovery After Photo-bleaching), and the like, have been known as methods for analyzing molecular interactions such as combination and separation of molecules or aggregation and diffusion of molecules. In the experiments of FRET and FRAP, it is required that acquisition of an image of an observation object, and optical stimulation of the observation object are synchronized with each other at a high speed and with a high accuracy. A scanning laser microscope for performing such experiments is known (see, for example, Patent Literature 1).
The scanning laser microscope described in Patent Literature 1 is configured to perform the experiment of FRET or FRAP in such a manner that an observation position, and the output power of laser light radiated to the observation position, and also a stimulation position, and the output power of laser light radiated to the stimulation position are registered in a system, and that the observation and optical stimulation of a sample are performed on the basis of the registered observation and stimulation positions, and on the basis of the registered output power of the laser light corresponding to each of the registered observation and stimulation positions.